Yann Arthus-Bertrand and Michael Pitiot turn their aerial cameras toward the sea, tracking how a system covering seventy percent of the planet has become entangled with human survival. The film moves from coral reefs to industrial fishing fleets to Arctic ice, using overhead shots that turn coastlines, trawler wakes, and shipping lanes into visible patterns of extraction and damage. Marine biologists and oceanographers appear throughout to explain what the footage shows: collapsing fish stocks, bleaching reefs, and plastic accumulating in currents far from any coastline. The film treats the ocean not as scenery but as infrastructure, the source of the oxygen, protein, and climate regulation that make the rest of the planet livable, and it lays out what happens as that infrastructure degrades. Rather than a single villain, it points to compounding pressures, overfishing, warming water, and runoff pollution, stacking up faster than ecosystems can absorb them. The aerial photography is the film's clearest asset, making abstract statistics about ocean health suddenly legible as landscape.